Technical Memorandum. Soil Borings

Technical Memorandum To: Project File and Appendix F to Sediment Remedial Investigation Report From: Sara L. Leow, PE Subject: Geotechnical Investigation and Results Summary Date: February 213 Project: U.S. Steel Spirit Lake Sediment Investigation Overview A geotechnical investigation was performed in conjunction with the remedial investigation for the U.S. Steel (USS) Spirit Lake Sediment Investigation project during the summer and fall of 211. The geotechnical investigation served to document general geotechnical soil characteristics across the site by means of field and laboratory testing. This memo presents a summary of the geotechnical field and laboratory testing data collected during the investigation. This memo is to accompany the associated Sediment Remedial Investigation Report (RI Report). Please refer to the RI report for complete project description, background information, site figures, and environmental data. Field Testing The geotechnical field investigation consisted of soil borings, standard penetration tests (SPT), cone penetration test (CPT) soundings, pore-pressure dissipation (PPD) testing, flat plate dilatometer (DMT) testing, and vane shear testing (VST). The locations of the Fall 211 geotechnical borings are presented on Figure F-1. Boring logs, CPT logs, pore-water dissipation plots, DMT data, and lab testing data are included in this memo as attachments F-1 through F-4. Each of the field tests is described below, and results of field data are shown in the attached Table F-1 or in attached report sheets, as applicable. Soil Borings Soil borings were completed at several locations within the Unnamed Creek (UC) and Wire Mill areas. Soil borings were initially denoted with a solely numerical label, and subsequently renamed to include a UC or WM to designate of the area where the test boring was performed. The old boring number is provided in parentheses next to the new denotation in this document. Soil borings were performed at six locations at the site, including three in the Unnamed Creek area: UC-94 (34), UC-96 (3), and UC-97 (39); as well as three in the Wire Mill area: WM-1 (311), WM-11 (314), and WM-12 (31) (Figure F-1). Each test boring was performed in general accordance with ASTM D186 from a balloon-tired drill rig mounted on a barge, and were extended to a depth of 2

To: Project File and Appendix F to Sediment Remedial Investigation Report From: Sara L. Leow, PE Subject: Geotechnical Investigation and Results Summary Date: February 213 Page: 2 Project: U.S. Steel Spirit Lake Sediment Investigation to 36. feet below the riverbed. The borings were advanced using hollow stem auger. Continuous sampling was performed with a standard split spoon for two test borings, UC-94 (34) and WM-1, and with a modified California sampler for the remaining four test borings. Shelby (thinwall) tube samples were collected at select intervals per ASTM D197, with the majority collected in offset borings. USCS soil classifications are shown on the geotechnical test boring logs, provided as attachments. In general, the subsurface conditions consist of organic silt or peat underlain by layers of lean clay, sandy clay, silt, sandy silt, sand, and silty sand. In some cases, multiple layers of peat were encountered, separated by layers of clay, silt, and/or sand. Due to the complex depositional environment at the site, soils with the same USCS symbols may have different geotechnical properties. Soil types and properties should be further assessed at specific locations and depths for design as part of future project phase(es). Standard Penetration Tests Blow counts were recorded per each 6-inch drive of a standard split spoon over a two-foot interval for SPT performed at two soil borings, UC-94 (34) and WM-1 (311) (see Figure F-1). The SPT N-value is calculated as the sum of the blow counts for the second and third 6-inch drives. The uncorrected SPT N-values are shown on the boring logs. N-values ranged from less than 1 to 16, with the majority between less than 1 and 7. It should be noted that although blow counts were recorded while sampling with the modified California sampler, those blow counts were not considered viable for future geotechnical design since a correlation cannot reliably be made between SPT N-values and blow counts recorded while driving a modified California sampler. Cone Penetration Test Soundings CPT soundings were performed at twelve locations from equipment mounted to a barge in general accordance with ASTM D778, each to a depth of feet below the riverbed. The associated test boring is designated in parentheses after the CPT number. Seven CPT soundings, CPT-31 (UC-94), CPT-33 (UC-93), CPT-34 (UC-92), CPT-3 (UC-96), CPT-36 (UC-9), CPT-37 (UC-98), and CPT-39 (UC-97) were performed in the Unnamed Creek area, and five CPT soundings, CPT-31 (WM-99), CPT- 311 (WM-1), CPT-314 (WM-11), CPT-31 (WM-12), and CPT-316 (WM-13) were performed in the Wire Mill area (Figure F-1). CPT logs are attached. Similar to the conditions encountered in the soil borings, the CPT soundings indicate subsurface conditions consisting of layers of clay, silt, and sand. Based on the CPT results, the undrained shear strengths of cohesive soils (clays) range from approximately 1 to greater than 2, pounds per square foot (psf). For non-cohesive soils (sand and silt), the angle of internal friction ranges from approximately 28 degrees to greater than 4 degrees based on the CPT results. Attached Figures F-2 and F-3 graphically depict the undrained shear strength and angle of internal friction ranges. P:\Duluth\23 MN\69\2369112 St Louis River Duluth Works Sediment\WorkFiles\N-RI Report_212\Appendices\Appendix F - Geotechnical Evaluation\Geotechnical Tech Memo 2-28-13.docx

To: Project File and Appendix F to Sediment Remedial Investigation Report From: Sara L. Leow, PE Subject: Geotechnical Investigation and Results Summary Date: February 213 Page: 3 Project: U.S. Steel Spirit Lake Sediment Investigation Pore Pressure Dissipation Tests PPD was also performed at select intervals during CPT testing per ASTM D778. PPD test data is available from CPT-33 (UC-93), CPT-34 (UC-92), CPT-314 (WM-11), and CPT-316 (WM-13) at approximate depths of 4.6, 4.6, 31.8, and 4.8 feet below the riverbed, respectively (Figure F-1). Soil coefficients of permeability from the PPD tests range from x1-8 to 2x1 - centimeters per second (cm/s). The time duration to reach % dissipation (t ) mainly varied between.33 and.67 minutes, although a t of 3.92 minutes was calculated for the dissipation test performed at CPT-33 (UC-93). PPD plots are attached to this memo. Flat Plate Dilatometer Testing DMT testing was performed to document soil characteristics to, in conjunction with consolidation lab testing, aid in settlement assessment during future project phases. DMT was performed in general accordance with ASTM D663 at locations offset from four CPT soundings, CPT-31 (UC-94), CPT-36 (UC-9), CPT-3 (UC-96), and CPT-311 (WM-1) (Figure F-1). DMT testing was performed at select intervals to termination depths of approximately 1 to 37 feet below the sediment surface. DMT data is attached. In-Situ Vane Shear Testing Vane shear testing was performed to document shear strength of soft soils at various depths in general accordance with ASTM D273. Vane shear testing of near-riverbed surface soils was initially attempted through the ice in March 211; however, the strength of the surficial sediments did not provide the resistance necessary to record readings with the field equipment available at the time. A more sensitive vane shear tool was obtained, and vane shear testing was performed at depths below the riverbed of feet and shallower in June 211. The results of shallow vane shear testing near the riverbed performed in June 211 indicate peak undrained shear strengths between approximately 37 and 1,6 psf; a summary of the results is provided in Table F-1. The strength values attained from this testing period are considered preliminary. Factors such as performing the test from a moving platform affixed to a small boat and approximations of test depths relative to variable water surface elevations may have affected the data. The recorded shear strength for some intervals may also be arbitrarily high due to the presence of debris in some near-surface soil layers. Additional vane shear testing should be performed to further document strengths for near-riverbed surface soils for design. Additional vane shear testing was performed at depths below the riverbed generally greater than feet in November 211. A summary of the results from the vane shear testing is presented in Table F-1. Results of vane shear tests performed at greater depths in November 211 indicate that peak undrained shear strengths range between 32 and 99 psf, while remolded shear strengths range between 32 and 31 psf. P:\Duluth\23 MN\69\2369112 St Louis River Duluth Works Sediment\WorkFiles\N-RI Report_212\Appendices\Appendix F - Geotechnical Evaluation\Geotechnical Tech Memo 2-28-13.docx

To: Project File and Appendix F to Sediment Remedial Investigation Report From: Sara L. Leow, PE Subject: Geotechnical Investigation and Results Summary Date: February 213 Page: 4 Project: U.S. Steel Spirit Lake Sediment Investigation Laboratory Testing Laboratory testing was performed on select samples to further document soil properties. The laboratory testing performed and associated methods are listed below, followed by a description of each test and summary of test results. Test results are also presented in the attached Table F-1, as well as in attached laboratory test reports. Moisture Content tests per ASTM D2216, Standard Test Method for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass. Unit Weight tests per ASTM D7263, Standard Test Methods for Laboratory Determination of Density (Unit Weight) of Soil Specimens. Grain Size and Hydrometer Analyses per ASTM D422, Standard Test Method for Particle-Size Analysis of Soils. Atterberg Limits per ASTM D4318, Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils. Permeability testing per ASTM D8, Standard Test Methods for Measurement of Hydraulic Conductivity of Saturated Porous Materials Using Flexible Wall Permeameter. Consolidation testing per ASTM D243, Standard Test Methods for One-Dimensional Consolidation Properties of Soils Using Incremental Loading. Triaxial Compressive Strength per ASTM D28, Standard Test Method for Consolidated Undrained Triaxial Compression Test for Cohesive Soils. Organic Content tests per ASTM D2974, Standard Test Methods for Moisture, Ash, and Organic Matter of Peat and other Organic Soils. In addition to the samples discussed below, laboratory testing consisting of moisture content, unit weight, Atterberg Limits, organic content, and consolidated undrained (CU) triaxial testing were performed on a Shelby tube sample collected between the depths of 17. to 2 feet below riverbed at test boring UC-96 (3). Further review of this information indicated significantly different laboratory test results than anticipated based on similar materials encountered at the site. As such, it is recommended that the lab test data from the 17. to 2 foot Shelby tube sample from test boring UC-96 (3) should not be used for analyses. P:\Duluth\23 MN\69\2369112 St Louis River Duluth Works Sediment\WorkFiles\N-RI Report_212\Appendices\Appendix F - Geotechnical Evaluation\Geotechnical Tech Memo 2-28-13.docx

To: Project File and Appendix F to Sediment Remedial Investigation Report From: Sara L. Leow, PE Subject: Geotechnical Investigation and Results Summary Date: February 213 Page: Project: U.S. Steel Spirit Lake Sediment Investigation Moisture Content Tests Moisture content tests were performed on eight Shelby (thinwall) tube samples collected from borings UC-94 (34), UC-96 (3), WM-1 (311), and WM-11 (314) (Figure F-1). Results of tests on these samples indicate a moisture content range of approximately 24 to 97 percent, with the higher moisture contents generally associated with soils containing organics (peat, organic silt, or organic clay). Unit Weight Tests Unit weight tests were also performed on eight Shelby tube samples collected from borings UC-94 (34), UC-96 (3), WM-1 (311), and WM-11 (314) (Figure F-1). The dry unit weights of these samples range from 48 to 14 pounds per cubic foot (pcf), and the moist unit weights vary from 9 to 128 pcf. The lower densities are generally associated with materials containing organics. Grain Size Analyses Grain size analysis tests, including both sieve and hydrometer tests, were performed on several nearsurface (shallower than approximately feet) soil samples collected via vibracore methods at UC-11, UC- 23, UC-29, WM-3, WM-1, WM-18, WM-21, WM-3, and WM-32. Vibracore samples were collected mainly for the intention of environmental analyses. Gradation tests were also performed on three Shelby tube samples from test borings UC-96 (3), WM-1 (311), and WM-11 (314) (Figure F-1). Test results indicate that near-surface soil samples contain gravel, sand, silt, and clay ranges of to 3.8 percent,.8 to 97.4 percent, 1.6 to 89.1 percent, and 1 to 28. percent, respectively. Gradation results for the Shelby tube samples indicate soils containing gravel, sand, silt, and clay ranges of zero percent,.1 to 13. percent, 72. to 91.3, and 6.1 to 14 percent, respectively. Atterberg Limits Tests Atterberg Limits tests were performed on several near-surface vibracore soil samples from locations UC- 11, UC-23, UC-29, WM-3, WM-1, WM-18, WM-21, WM-3, and WM-32 (Figure F-1). Atterberg limits tests were also performed on the eight Shelby tube samples collected from borings UC-94 (34), UC-96 (3), WM-1 (311), and WM-11 (314) (Figure F-1). Test results indicate the liquid limit ranges from 23 to 123 percent, the plastic limit ranges from 19 to 2 percent, and the plasticity index ranges from 1 to 73 percent. Atterberg limits results of the tested samples indicate near-surface soils (shallower than approximately feet) consist of fat clay (CH), high plasticity silt/high plasticity organic silt (MH/OH), low plasticity silt/low plasticity organic silt (ML/OL), and low plasticity clay/low plasticity organic clay (CL/OL). Atterberg limits tests on deeper soils indicate silt (ML), lean clay (CL), and silty clay (CL-ML) soils. Permeability Tests Permeability tests were performed on three Shelby tube samples collected from UC-96 (3), WM-1 (311), and WM-11 (314) (Figure F-1). The tests indicate coefficients of permeability between approximately 3.x1-7 to 2.x1-6 cm/s. P:\Duluth\23 MN\69\2369112 St Louis River Duluth Works Sediment\WorkFiles\N-RI Report_212\Appendices\Appendix F - Geotechnical Evaluation\Geotechnical Tech Memo 2-28-13.docx

To: Project File and Appendix F to Sediment Remedial Investigation Report From: Sara L. Leow, PE Subject: Geotechnical Investigation and Results Summary Date: February 213 Page: 6 Project: U.S. Steel Spirit Lake Sediment Investigation Consolidation Tests Consolidation testing was performed on two Shelby tube samples collected from test borings UC-94 (34) and UC-96 (3) (Figure F-1). The testing indicates coefficients of consolidation between.13 to.73, and coefficients of recompression from.1 to.3. This data will be used in conjunction with DMT testing data to aid in settlement evaluation for future project phases. Consolidated Undrained (CU) Triaxial Tests CU triaxial tests were performed on two Shelby tube samples collected from test borings UC-94 (34) and WM-1 (311) (Figure F-1) to document strength characteristics. Test results indicate drained angles of internal friction between approximately 34 and 36 with an associated drained cohesion value of psf. Closing This memo has presented a summary of the geotechnical investigation performed as part of the USS Spirit Lake Sediment Investigation. Soil characteristics discussed in this memo will be further evaluated and employed as applicable to designs for environmental remediation efforts developed during future project phases. Attachments: Table F-1 Geotechnical Field and Laboratory Data Summary Figure F-1 Fall 211 Geotechnical Boring Locations Figure F-2 Graph, Undrained Shear Strength from CPT vs. Depth Figure F-3 Graph, Friction Angle vs. Depth Attachment F-1 Boring Logs Attachment F-2 CPT Logs Attachment F-3 Pore Pressure Dissipation Plots Attachment F-4 DMT Data Attachment F- Laboratory Testing Data P:\Duluth\23 MN\69\2369112 St Louis River Duluth Works Sediment\WorkFiles\N-RI Report_212\Appendices\Appendix F - Geotechnical Evaluation\Geotechnical Tech Memo 2-28-13.docx

Tables

Sample Location ID Sample Type Depth (ft) Top Bottom Average USCS Soil Classification Soil Classification Notes SPT Data Incremental Blow Counts 1 2 3 4 N Value Moisture Content Table F-1: Geotechnical Field and Lab Data Summary Dry Density (pcf) Moist Density Atterberg Limits LL PL PI Grain Size Analysis Consolidation CU Triax c' ' % Gravel % Sand % % Clay p ' (tsf) C c C r e (%) (pcf) (%) (%) (%) (psf) (deg) (%) UC 11 in situ..3.2 CH/OH 37* UC 11 in situ 1.6 2. 1.8 ML/OH 74* UC 11 VC. 1.. CH/OH 1 44 6. 3.6 81 14.9 UC 11 VC 1. 2. 1. MH/OH 6 4 11 3.4 86.6 1 UC 11 VC 2. 3. 2. MH/OH 61 48 13.6.2 81.2 13 UC 11 in situ 3.3 3.6 3. ML/OH 26* UC 11 in situ 4.9.3.1 PT 298* UC 23 in situ..3.2 CH/OH 74* UC 23 VC...3 CH/OH 123 73 2. 82.6 14.9 UC 23 VC 1. 2. 1.8 MH/OH 72 42 3 2.2 82.8 1 UC 23 in situ 1.6 2. 1.8 ML/OH 74* UC 23 VC 2. 3. 2.8 MH/OH 74 44 3 2.4 82.1 1. UC 23 in situ 3.3 3.6 3. MH/OH 298* UC 23 VC 3.8 4.3 4. SM with Peat NP NP NP 72.1 2.9 2 UC 29 in situ..3.2 CH/OH 37* UC 29 VC...3 CH/OH 1 44 61 1.9 82.6 1. UC 29 VC 1. 1. 1.3 MH/OH 61 42 19 3.3 83.7 13 UC 29 in situ 1.6 2. 1.8 MH/OH 26* UC 29 VC 2. 2. 2.3 CH/OH 9 41 4 1.8 74.7 23. UC 29 VC 2. 3. 2.8 ML/OL 34 29 2.6 64.4 1 UC 29 in situ 3.3 3.6 3. ML 8* UC 79 in situ..3.2 SM/OL 744* UC 8 in situ..3.2 ML weakly cemented, with crystals 13* UC 81 in situ..3.2 SM 77* UC 83 in situ..3.2 SM 372* UC 83 in situ 1.6 2. 1.8 SM 9* UC 93 (33) in situ.9 ML 3.92 2.E 6.E 8 UC 94 (34) SS. 2. 1. OL Mainly organic silt underlain by PT, SC, and SP WH WH 1 2 1 UC 94 (34) SS 2. 4. 3. CL WH WH WH WH <1 UC 94 (34) in situ 4.6 SM.33 2.E 4.E 7 UC 94 (34) SS 4. 6.. ML and CL ML between 4 4.8 ft, otherwise CL WH WH 1 1 1 UC 94 (34) SS 6. 8. 7. CL and SP CL to 7.2, then SP 1 3 1 1 4 UC 94 (34) SS 8. 1. 9. CL ML Sandy 1 1 WH 1 1 UC 94 (34) SS 1. 12. 11. ML May also consist of CL and SP 1 1 WH 2 1 UC 94 (34) TW**** 1. 13. 11.8 ML Sandy to with Sand 24.6 11.2 126.2 36.2 UC 94 (34) TW 1. 13. 11.8 ML Sandy 23. 13.7 128.1 23.4 2.4 3 9.13.1.644 UC 94 (34) SS 12. 14. 13. CL Sandy with 3 2 3 2 UC 94 (34) in situ 14. CL Sandy 92 16 UC 94 (34) SS 14. 16. 1. CL/SP CL to 14.8 then SP 2 3 2 2 UC 94 (34) SS 16. 18. 17. SP/CL SP to 17.4, then Sandy CL 1 1 1 1 2 UC 94 (34) SS 18. 2. 19. SM with Clay WH 1 1 1 2 UC 94 (34) SS 2. 22. 21. SP SM/CL SP SM to 21.4, then CL 1 3 2 1 UC 94 (34) SS 22. 24. 23. SP WH 1 1 3 2 UC 94 (34) SS 24. 26. 2. SP 3 3 3 3 6 UC 94 (34) SS 26. 28. 27. SP/SC SP to 27.2, then SC 3 2 1 1 3 UC 94 (34) SS 28. 3. 29. SP 1 1 2 4 3 UC 9 (34) in situ. CL Sandy 9 38 UC 96 (3) in situ 3. ML 9 32 UC 96 (3) TW (top). 7. 6.3 CH/OH Extremely soft and wet, potential petroleum contaminants 92.7.3 96.9.41.73.3 2.97 UC 96 (3) TW (middle). 7. 6.3 CH/OH Extremely soft and wet, potential petroleum contaminants 96.7 48.3 9. 78.6 41.8 36.8 2.6 91.3 6.1 2.E 6 UC 96(3) TW (bottom). 7. 6.3 ML 46.8 34. 12.3 UC 96 (3) in situ 8. OL Organic 28 38 UC 96 (3) TW 17. 2. 18.8 CL with organics 114.3 41. 89.19 11. 9.6 UC 96 (3) in situ 22. CL 16 86 UC 96 (3) TW 22. 2. 23.8 CL WM 1 in situ..3.2 SM 186* WM 1 in situ 1.6 2. 1.8 ML 372* WM 1 in situ 3.3 3.6 3. CL mixed with fibrous peat 9* WM 3 VC. 1.. MH/OH 8 39 19 14.8 7 1.2 WM 3 VC 2. 4. 3. ML/OL 4 3 1 17.6 74.4 8 WM 3 VC 4.2 4.8 4. ML/OL 4 28 17.1 77.9 17 WM 3 VC 4.8.3. CL/OL 36 21 1 2.8 76.7 2. WM 1 PC. 1.. ML/OL 3 2 1 78. 6. WM 1 PC 1. 2. 1. ML/OL 42 28 14 3.9 89.1 7 WM 1 PC 2. 2.8 2.4 PT NP NP NP.6 24.4 6. 9. WM 18 VC/PC..7.4 CH/OH 91 39 2 3.6 81.4 1 WM 18 VC/PC.7 1.7 1.2 MH/OH 8 33 2.1 82.9 12 WM 18 VC/PC 1.7 2.7 2.2 MH/OH 7 48 27 8. 78 13. WM 21 VC/PC...3 MH/OH 69 33 36 6.6 79.4 14 WM 21 VC/PC 2. 2. 2.3 MH/OH 84 37 47.8 76.2 23 WM 21 VC/PC 4. 4. 4.3 MH/OH 16 2 4 2.4 73.6 24 WM 21 VC/PC...3 MH/OH 98 44 4 1 7. 28. WM 3 VC/PC...3 MH/OH 9 4 14.3 44.9 47.8 7 WM 3 VC/PC 1. 1. 1.3 PT/ML Peat to 1.2', ML below 1.2', ML is sandy NP NP NP 46.1 47.9 6 WM 3 VC/PC 2. 2. 2.3 ML/OL 37 28 9 27.2 6.8 7 WM 3 VC/PC 3. 4. 3.8 SC 26 2 1 19.4 73.1 7. WM 32 VC/PC...3 ML/OL 41 26 1.2 27.3 62. 1 WM 32 VC/PC. 1..8 ML/OL 33 24 9.1 23.9 66 1 WM 32 VC/PC 1. 1. 1.3 SM % charred woodchips NP NP NP 3.8 81.6 12.1 2. WM 32 VC/PC 3. 4. 3.8 SP NP NP NP 97.4 1.6 1 WM 33 in situ..3.2 PT silty 186* WM 33 in situ 1.6 2. 1.8 CL with peat 223* WM 33 in situ 3.3 3.6 3. CL 186* WM 42 in situ..3.2 PT with silty sand 21* WM 42 in situ 1.6 2. 1.8 PT with silty sand 8* Organic Content Permeability (cm/s) Peak Strength, s u (psf) VST Remolded Strength, s ur (psf) t (min) PPD k, high end (cm/s) k, low end (cm/s)

Table F-1: Geotechnical Field and Lab Data Summary (cont.) Sample Location ID Sample Type Depth (ft) Top Bottom Average USCS Soil Classification Soil Classification Notes SPT Data Incremental Blow Counts 1 2 3 4 N Value Moisture Content Dry Density (pcf) Moist Density (%) (pcf) (%) (%) (%) (psf) (deg) (%) WM 42 in situ 3.3 3.6 3. ML trace to with organics 113* WM 43 in situ..3.2 ML/OL 149* WM 43 in situ 1.6 2. 1.8 ML/OL 186* WM 43 in situ 3.3 3.6 3. PT y 93* WM 4 in situ..3.2 SM trace organics 744* WM 4 in situ 1.6 2. 1.8 SP 141* WM 4 in situ 3.3 3.6 3. SP 16* WM 63 in situ..3.2 ML/OL lenses of Sand 186* WM 63 in situ 1.6 2. 1.8 SM trace to with organics, trace metallic particles and shells 149* WM 63 in situ 3.3 3.6 3. SM 123* WM 71 in situ..3.2 SP with metallic particles 149* WM 71 in situ 1.6 2. 1.8 SP with metallic particles 142* WM 73 in situ..3.2 ML/OL 298* WM 73 in situ 1.6 2. 1.8 ML with Peat 93* WM 73 in situ 3.3 3.6 3. ML with Peat 113* WM 1 (311) SS. 2. 1. OL/SP Organic ML to 1.4, then SP WH WH 1 WH 1 WM 1 (311) SS 2. 4. 3. SP/CL ML SP to 3, then CL ML WH WH WH WH <1 WM 1 (311) TW 3.. 4.3 CL with Sand, trace Peat 28.3 94 12.6 28. 19.8 8.7 13. 72. 14 3.E 7 WM 1 (311) SS 4. 6.. CL with Sand, trace Peat WH WH WH WH <1 WM 1 (311) in situ 6. CL 28 32 WM 1 (311) SS 6. 8. 7. CL ML with Sand, trace Peat WH WH WH WH <1 WM 1 (311) SS 8. 1. 9. CL ML with Sand and Peat WH WH WH WH <1 WM 1 (311) in situ 1. ML Sandy 678 N/A** WM 1 (311) SS 1. 12. 11. ML Sandy, 'milled' wood fill 1.4 1.6 WH WH 3 3 3 WM 1 (311) in situ 11. CL 99 31 WM 1 (311) SS 12. 14. 13. ML Trace gravel WH 4 4 8 8 WM 1 (311) TW 12. 14. 13.3 ML Sandy 23.7 1 123.7 34.8 WM 1 (311) SS 14. 16. 1. SM Trace gravel 1.6 1.8 3 8 8 7 16 WM 1 (311) in situ 16. SM 688 237 WM 1 (311) SS 16. 18. 17. SM/CL SM to 17.2, then CL 6 1 7 WM 1 (311) SS 18. 2. 19. SP 3 3 3 6 WM 1 (311) SS 2. 22. 21. SP 3 3 3 4 6 WM 1 (311) SS 22. 24. 23. SP 2 4 3 7 WM 1 (311) SS 24. 26. 2. SP 1 4 6 7 1 WM 1 (311) SS 26. 28. 27. SP 2 4 1 6 14 WM 1 (311) SS 28. 3. 29. CL/SP CL to 28.8, SP to 29.6, then CL 4 4 2 WH 6 WM 1 (311) SS 3. 32. 31. CL WH WH WH 2 <1 WM 1 (311) SS 32. 34. 33. CL ML/CL CL ML to 32, then CL WH WH 2 2 2 WM 1 (311) TW 34. 36. 3.3 CL WM 11 (314) in situ. ML 32 N/A** WM 11 (314) in situ 1. ML 183 22*** WM 11 (314) TW 27. 3. 28.8 CL ML 31.2 88.6 116.2 28.1 21.4 6.7.1 9.1 9.8 1.1E 6 WM 11 (314) in situ 31.8 CL ML.67 1.1E 1.7E 7 WM 13 (316) in situ 4.8 ML.9 1.3E 2.E 7 *Values may have been affected by testing conditions and debris **Remolded value could not be recorded due to test malfunction ***Value may not be representative; vane settled during test ****Material changed between specimens, CU data based on two points for similar materials Lab testing results are significantly different than anticipated based on other similar materials encountered at the site. Lab test data should not be used for analyses LL Atterberg Limits Grain Size Analysis Consolidation CU Triax PL PI c' ' % Gravel % Sand % % Clay p ' (tsf) C c C r e Organic Content Permeability (cm/s) Peak Strength, s u (psf) VST Remolded Strength, s ur (psf) t (min) PPD k, high end (cm/s) k, low end (cm/s)

Figures

8 9 6 8 9 " / Unnamed Creek Delta 9 (! 6 93 UC-97!!(. 98 9 9 UC-79 9 6 1 6 9 62 Spirit Lake 9 7 6 6 Spirit Island 6 62 93 94 UC-11 6 Unna me dc 4 9 63 UC-98 " / 6 9 (! ( UC-8! ek 93 UC-23 UC-9 / " re 8 4 /" " / Ë ) 9 9 UC-81 9 96! ((!!. (! UC-96 / " (! ) UC-83 Ë 61 99 ( UC-94! " / Ë )!. UC-29 /" (! UC-93 /" Morgan Park Barr Footer: ArcGIS 1.1, 213-2-13 14:1 File: I:\Client\USS_Duluth_Works\Work_Orders\Winter_212\Maps\Reports\RI Report\Appendix F\Figure F-1 Fall 211 Geotechnical Boring Locations.mxd User: jlc 7 9 8 " / 8 UC-92 98 6 6 9 3 94 93 98 Wire Mill Delta /" Approximate U. S. Steel Operations Area 97 92 WM-21 8 99 " / Ë )!. WM-1 9 97 96 98 79 97 8 94 9 8 8 96 " WM-99 / 9 8 94 98 9 6 8 Elevation approx. 61.8 feet /" WM-18 (! 7 9 96 9 9 8 9 WM-3 98 WM-32 MI NN ES W IS CO OTA NS IN 8 7 86 88 8 6 /" 6 /" 99 (! 1 9 99 63 (! 98 WM-42 97 WM-3 94 WM-11 /" /" " WM-13 / WM-1 l ne n ha rc 9 3!. " / 63 WM-33 e Riv s i u St. L o WM-12 " /!. Wire Mill Pond 6 62 9 92 9 9 7 8 79 " / Core Penetration Test (CPT) Sounding Location ) Ë Flate Plate Dilatometer Test (DMT) Location!. Hollow Stem Auger (HSA) Soil Boring Location /" (! Vane Shear Locations ;! N 1, 2, Feet Vibracore Sample Collection Locations Bathymetry Contour (1-Foot) Approximate Outer Study Area Limit Approximate Location of St. Louis River Channel, Based on Orthophoto Interpretation Approximate U. S. Steel Operations Area (URS, 28) Figure F-1 FALL 211 GEOTECHNICAL BORING LOCATIONS Spirit Lake Sediment Site Former U. S. Steel Duluth Works Saint Louis River Duluth, Minnesota

Undrained Shear Strength, s u [psf] 1, 1, 2, 2, 3, UC-92 UC-93 UC-94 1 UC-9 UC-96 UC-96A UC-97 2 UC-98 WM-1 WM-11 WM-12 Depth [ft] 3 WM-13 WM-99 4 6 Figure F-2. Undrained Shear Strength from CPT vs. Depth (N kt =16)

Friction Angle, ' [degrees] 1 2 3 4 6 7 UC-92 UC-93 UC-94 1 1 2 UC-9 UC-96 UC-96A UC-97 UC-98 WM-1 WM-11 Depth [ft] 2 3 WM-12 WM-13 WM-99 3 4 4 6 Figure F-3. Friction Angle vs. Depth (Robertson & Campanella, 1983)

Attachments

Attachment F-1 Soil Boring Logs

C:\USERS\SLL\DESKTOP\PROJECTS\USS\USS SPIRIT LAKE GEOTECHNICAL.GPJ BARR ENGINEERING_LIB.GLB BOREHOLE LOG REPORT BARR ENGINEERING.GDT Project: Spirit Lake Sediment Site Job No.: 23/69-112.3-1-2 Location: Duluth, MN Coordinates: N 399,372.2 ft E 2,81,39.7 ft Datum: Elevation, feet 9. 92. 9. 87. 8. 82. 8. 77. Depth, feet. 2.. 7. 1. 12. 1. 17. Barr Engineering Company 332 W. Superior St. Suite 6 Duluth, MN 82 Telephone: 218-727-218 9.9 ft Surface Elev.: ORGANIC SILT (OL): very dark brown; wet. 94. ft PEAT (PT): very dark brown; wet. 94.3 ft CLAYEY SAND (SC): very dark brown; wet. 94.1 ft SAND (SP): fine grained; very dark brown; wet. 93.9 ft SANDY CLAY (CL): very dark gray; moist; very soft. 91. ft SILT (ML): very dark gray; wet. 91.1 ft LEAN CLAY (CL): very dark gray; moist..': Vane shear test. 88.7 ft SAND (SP): fine to medium grained; very dark gray; wet. 87.9 ft LEAN CLAY (CL): very dark gray; moist. 87.6 ft 8.-1.': Shelby tube, no recovery. SILTY CLAY (CL-ML): very dark gray; wet; very soft. 8.9 ft LEAN CLAY (CL): very dark gray; wet. 8. ft SILT (ML): very dark gray; wet. 8.1 ft 1.-13.': Shelby tube, 18 inches recovery. SAND (SP): very dark gray; wet. 84.3 ft LEAN CLAY (CL): very dark gray; wet. 83.9 ft SANDY CLAY (CL): brown; moist to wet; medium stiff. 81.1 ft 14.': Vane shear test. SAND (SP): fine to medium grained; brown; wet. 78. ft SANDY CLAY (CL): brown; moist. 17.-2.': Shelby tube, no recovery. 77.9 ft SILTY SAND (SM): brown; wet; very loose. 2. 7.9 ft Continued Next Page Date Boring Started: 11/8/11 Date Boring Completed: 11/8/11 Logged By: IGM Drilling Contractor: EPC Drill Rig: MATERIAL DESCRIPTION Water Levels (ft) Surface Elevation: Drilling Method: Sampling Method: Completion Depth: 1.4ft 1.6ft 1.8ft 2.ft 4.4ft 4.8ft 7.2ft 8.ft 8.3ft 1.ft 1.4ft 1.8ft 11.6ft 12.ft 14.8ft 17.4ft 18.ft 9.9 ft 3.2" HSA SS 3. ft 1 1 4 6 6 1 WH 1 4 1 1 2 2 Sheet 1 of 2 1 2 3 4 REC% RQD % 2 4 6 8 Remarks: Vane shear testing performed and Shelby tubes were collected in boring offset 12 feet. Weather: LOG OF BORING UC-94 (34) Graphic Log Samples Sample No. % Recovery SPT, N value or RQD % STANDARD PENETRATION TEST DATA N in blows/ft STRENGTH, psf 1 1 1 1 1 2 2 4

Project: Spirit Lake Sediment Site Job No.: 23/69-112.3-1-2 Location: Duluth, MN Coordinates: N 399,372.2 ft E 2,81,39.7 ft Datum: Elevation, feet Depth, feet Barr Engineering Company 332 W. Superior St. Suite 6 Duluth, MN 82 Telephone: 218-727-218 MATERIAL DESCRIPTION Surface Elevation: Drilling Method: Sampling Method: Completion Depth: LOG OF BORING UC-94 (34) 9.9 ft 3.2" HSA SS 3. ft Graphic Log Samples Sample No. % Recovery SPT, N value or RQD % Sheet 2 of 2 STANDARD PENETRATION TEST DATA N in blows/ft 1 2 3 4 REC% RQD % 2 4 6 8 STRENGTH, psf C:\USERS\SLL\DESKTOP\PROJECTS\USS\USS SPIRIT LAKE GEOTECHNICAL.GPJ BARR ENGINEERING_LIB.GLB BOREHOLE LOG REPORT BARR ENGINEERING.GDT 7. 72. 7. 67. 2. 22. 2. 27. 3. SAND (SP): brown; wet. 74. ft LEAN CLAY (CL): brown; moist. 73.9 ft SAND (SP): fine to medium grained; dark yellowish brown; wet; very loose to loose. 68.7 ft SANDY CLAY (CL): dark yellowish brown; moist to wet. 67.9 ft SAND (SP): fine to medium grained; dark yellowish brown; wet; very loose. 6.9 ft Date Boring Started: 11/8/11 Date Boring Completed: 11/8/11 Logged By: IGM Drilling Contractor: EPC Drill Rig: Bottom of Boring at 3. feet Water Levels (ft) 2.ft 21.4ft 22.ft 27.2ft 28.ft 3.ft 6 7 1 7 9 Remarks: Vane shear testing performed and Shelby tubes were collected in boring offset 12 feet. Weather: 2 6 3 3 1 2 3 3 6

Project: Spirit Lake Sediment Site Job No.: 23/69-112.3-1-2 Location: Duluth, MN Coordinates: N 398,768. ft E 2,849,948.4 ft Datum: Elevation, feet Depth, feet Barr Engineering Company 332 W. Superior St. Suite 6 Duluth, MN 82 Telephone: 218-727-218 MATERIAL DESCRIPTION Surface Elevation: Drilling Method: Sampling Method: Completion Depth: LOG OF BORING UC-96 (3) 99. ft 4.2" HSA MC 3. ft Graphic Log Samples Sample No. % Recovery SPT, N value or RQD % Sheet 1 of 2 STANDARD PENETRATION TEST DATA N in blows/ft 1 2 3 4 REC% RQD % 2 4 6 8 STRENGTH, psf 97.. 99. ft Surface Elev.: SANDY SILT (ML): black; wet; with weakly cemented sandy material, trace shell fragments, apparent black staining from contaminants. 7 1 C:\USERS\SLL\DESKTOP\PROJECTS\USS\USS SPIRIT LAKE GEOTECHNICAL.GPJ BARR ENGINEERING_LIB.GLB BOREHOLE LOG REPORT BARR ENGINEERING.GDT 9. 92. 9. 87. 8. 82. 8. 2.. 7. 1. 12. 1. 17. 3.': Vane shear test..-7.': Shelby tube, 21 inches recovery. 91. ft ORGANIC SILT (OL): very dark brown; wet. 8.': Vane shear test. 89. ft SAND (SP): fine to medium grained; very dark grayish brown; wet. 89. ft PEAT (PT): very dark brown; wet. 88.7 ft LEAN CLAY (CL): dark gray; wet. 88. ft SAND (SP): fine to coarse grained; dark gray; wet. 82. ft LEAN CLAY (CL): brown; moist to wet; lens of peat at 2. feet. 2. Continued Next Page Date Boring Started: 1/31/11 Date Boring Completed: 1/31/11 Logged By: IGM Drilling Contractor: EPC Drill Rig: Water Levels (ft) 7.ft 9.ft 1.ft 1.3ft 1.ft 17.ft 92 6 3 3 67 Remarks: Shallow vane shear tests performed and Shelby tubes collected in offset boring. Weather:

Project: Spirit Lake Sediment Site Job No.: 23/69-112.3-1-2 Location: Duluth, MN Coordinates: Datum: Elevation, feet Depth, feet Barr Engineering Company 332 W. Superior St. Suite 6 Duluth, MN 82 Telephone: 218-727-218 MATERIAL DESCRIPTION Surface Elevation: Drilling Method: Sampling Method: Completion Depth: LOG OF BORING UC-96 (3) A 3.2" HSA MC 2. ft Graphic Log Samples Sample No. % Recovery SPT, N value or RQD % Sheet 1 of 2 STANDARD PENETRATION TEST DATA N in blows/ft 1 2 3 4 REC% RQD % 2 4 6 8 STRENGTH, psf. Surface Elev.: No samples collected - see UC-96 (3). 1 C:\USERS\SLL\DESKTOP\PROJECTS\USS\USS SPIRIT LAKE GEOTECHNICAL.GPJ BARR ENGINEERING_LIB.GLB BOREHOLE LOG REPORT BARR ENGINEERING.GDT 2.. 7. 1. 12. 1. 17. SILTY SAND (SM): black; wet; trace shell fragments and peat. ORGANIC SILT (OL): black; wet; trace clay. SAND (SP): fine to medium grained; dark grayish brown; wet. SILTY CLAY (CL-ML): dark brown. SAND (SP): fine to coarse grained; dark grayish brown. LEAN CLAY (CL): brown. 2. Continued Next Page Date Boring Started: 11/1/11 Date Boring Completed: 11/1/11 Logged By: JD (EPC) Drilling Contractor: EPC Drill Rig: Water Levels (ft).ft 7.ft 9.ft 1.ft 11.ft 17.ft 3 8 9 4 4 Remarks: Boring offset feet from UC-96 (3). Weather:

Project: Spirit Lake Sediment Site Job No.: 23/69-112.3-1-2 Location: Duluth, MN Coordinates: Datum: Elevation, feet Depth, feet Barr Engineering Company 332 W. Superior St. Suite 6 Duluth, MN 82 Telephone: 218-727-218 MATERIAL DESCRIPTION Surface Elevation: Drilling Method: Sampling Method: Completion Depth: LOG OF BORING UC-96 (3) A 3.2" HSA MC 2. ft Graphic Log Samples Sample No. % Recovery SPT, N value or RQD % Sheet 2 of 2 STANDARD PENETRATION TEST DATA N in blows/ft 1 2 3 4 REC% RQD % 2 4 6 8 STRENGTH, psf 2. LEAN CLAY (CL): brown. (Continued) 1 C:\USERS\SLL\DESKTOP\PROJECTS\USS\USS SPIRIT LAKE GEOTECHNICAL.GPJ BARR ENGINEERING_LIB.GLB BOREHOLE LOG REPORT BARR ENGINEERING.GDT 22. 2. Vane Shear test performed at 22 feet. Date Boring Started: 11/1/11 Date Boring Completed: 11/1/11 Logged By: JD (EPC) Drilling Contractor: EPC Drill Rig: Bottom of Boring at 2. feet Water Levels (ft) 7 2.ft Remarks: Boring offset feet from UC-96 (3). Weather:

Project: Spirit Lake Sediment Site Job No.: 23/69-112.3-1-2 Location: Duluth, MN Coordinates: N 398,9.7 ft E 2,8,626.7 ft Datum: Elevation, feet Depth, feet Barr Engineering Company 332 W. Superior St. Suite 6 Duluth, MN 82 Telephone: 218-727-218 MATERIAL DESCRIPTION Surface Elevation: Drilling Method: Sampling Method: Completion Depth: LOG OF BORING UC-97 (39) 99.7 ft 3.2" HSA MC 2. ft Graphic Log Samples Sample No. % Recovery SPT, N value or RQD % Sheet 1 of 2 STANDARD PENETRATION TEST DATA N in blows/ft 1 2 3 4 REC% RQD % 2 4 6 8 STRENGTH, psf. 99.7 ft Surface Elev.: SAND (SP): fine grained; black; wet. 99.2 ft SANDY SILT (ML): bluish black; moist; weakly cemented, laminations of white crystal pieces..ft 93 1 C:\USERS\SLL\DESKTOP\PROJECTS\USS\USS SPIRIT LAKE GEOTECHNICAL.GPJ BARR ENGINEERING_LIB.GLB BOREHOLE LOG REPORT BARR ENGINEERING.GDT 97. 9. 92. 9. 87. 2.. 7. 1. 12. 94.7 ft SILT (ML): very dark brown and black; moist; laminated, weakly cemented. Trace greenish, weakly cemented sandy material between approximately 6. and 7 feet. 92.7 ft PEAT (PT): very dark brown; moist; fibrous. 92.2 ft SILT (ML): very dark brown; wet. 89.7 ft PEAT (PT): very dark brown; moist to wet; fibrous. 86.2 ft SANDY SILT (ML): fine grained; dark grayish brown; moist to wet. Apparent milled wood pieces between approximately 13. and 13.7 feet. 8. 1. Continued Next Page Date Boring Started: 11/1/11 Date Boring Completed: 11/1/11 Logged By: IGM Drilling Contractor: EPC Drill Rig: Water Levels (ft).ft 7.ft 7.ft 1.ft 13.ft Remarks: Weather: 93 8 4 83 6

Project: Spirit Lake Sediment Site Job No.: 23/69-112.3-1-2 Location: Duluth, MN Coordinates: N 398,9.7 ft E 2,8,626.7 ft Datum: Elevation, feet Depth, feet Barr Engineering Company 332 W. Superior St. Suite 6 Duluth, MN 82 Telephone: 218-727-218 MATERIAL DESCRIPTION Surface Elevation: Drilling Method: Sampling Method: Completion Depth: LOG OF BORING UC-97 (39) 99.7 ft 3.2" HSA MC 2. ft Graphic Log Samples Sample No. % Recovery SPT, N value or RQD % Sheet 2 of 2 STANDARD PENETRATION TEST DATA N in blows/ft 1 2 3 4 REC% RQD % 2 4 6 8 STRENGTH, psf 1. SANDY SILT (ML): fine grained; dark grayish brown; moist to wet. (Continued) 83.7 ft SAND (SP): fine to medium grained; brown; wet. 16.ft 1 1 C:\USERS\SLL\DESKTOP\PROJECTS\USS\USS SPIRIT LAKE GEOTECHNICAL.GPJ BARR ENGINEERING_LIB.GLB BOREHOLE LOG REPORT BARR ENGINEERING.GDT 82. 8. 17. 2. 81.2 ft SILTY SAND (SM): fine grained; brown; wet. 81. ft LEAN CLAY (CL): brown; wet. 8.7 ft SAND (SP): fine grained; brown; wet. 79.7 ft Bottom of Boring at 2. feet Date Boring Started: 11/1/11 Date Boring Completed: 11/1/11 Logged By: IGM Drilling Contractor: EPC Drill Rig: Water Levels (ft) 18.ft 18.7ft 19.ft 2.ft Remarks: Weather: 93

Project: Spirit Lake Sediment Site Job No.: 23/69-112.3-1-2 Location: Duluth, MN Coordinates: N 39,879. ft E 2,849,78.6 ft Datum: Elevation, feet Depth, feet Barr Engineering Company 332 W. Superior St. Suite 6 Duluth, MN 82 Telephone: 218-727-218 MATERIAL DESCRIPTION Surface Elevation: Drilling Method: Sampling Method: Completion Depth: LOG OF BORING WM-1 (311) 98.7 ft 3.2" HSA SS 3. ft Graphic Log Samples Sample No. % Recovery SPT, N value or RQD % Sheet 1 of 2 STANDARD PENETRATION TEST DATA N in blows/ft 1 2 3 4 REC% RQD % 2 4 6 8 STRENGTH, psf 97.. 98.7 ft Surface Elev.: ORGANIC SILT (OL): very dark brown; wet; with sand, apparent black staining from contaminants below approximately 1 foot. 97.3 ft SILTY SAND (SM): brown; wet; trace peat. 1.4ft 4 1 1 1 C:\USERS\SLL\DESKTOP\PROJECTS\USS\USS SPIRIT LAKE GEOTECHNICAL.GPJ BARR ENGINEERING_LIB.GLB BOREHOLE LOG REPORT BARR ENGINEERING.GDT 9. 92. 9. 87. 8. 82. 8. 2.. 7. 1. 12. 1. 17. 9.7 ft SILTY CLAY (CL-ML): brown; wet; very soft; with sand. 3.-.': Shelby tube, 17. inches recovery. With peat between approximately 8 to 1 feet. 88.7 ft SANDY SILT (ML): brown; wet. 1.': Vane shear test. 88.1 ft Apparent milled wood pieces between 1.4 and 1.6 feet. SANDY SILT (ML): brown; wet; very loose to loose; gravel pieces at approximately 13.8 and 14 feet. 11.': Vane shear test. 12.-14.': Shelby tube, 14 inches recovery. 84.7 ft SILTY SAND (SM): yellowish brown; wet; medium dense. 1.': Vane shear test. Gravel between approximately 1.6 and 1.8 feet. 81. ft LEAN TO FAT CLAY (CL/CH): reddish brown; moist; lamination of sand at approximately 17.8 feet. 8.7 ft SAND (SP): fine grained; greenish gray; wet; loose to medium dense; lamination of sand at approximately 19.4 feet. 2. Continued Next Page Date Boring Started: 11/9/11 Date Boring Completed: 11/9/11 Logged By: JD (EPC) Drilling Contractor: EPC Drill Rig: Water Levels (ft) 3.ft 1.ft 1.6ft 14.ft 17.2ft 18.ft 2 9 1 8 6 4 4 WH WH WH WH Remarks: Vane shear testing performed and Shelby tubes (excluding 34-36.' Shelby tube) collected in an offset boring. Weather: 3 8 16 7 6 3 8 7 6 16

Project: Spirit Lake Sediment Site Job No.: 23/69-112.3-1-2 Location: Duluth, MN Coordinates: N 39,879. ft E 2,849,78.6 ft Datum: Elevation, feet Depth, feet Barr Engineering Company 332 W. Superior St. Suite 6 Duluth, MN 82 Telephone: 218-727-218 MATERIAL DESCRIPTION Surface Elevation: Drilling Method: Sampling Method: Completion Depth: LOG OF BORING WM-1 (311) 98.7 ft 3.2" HSA SS 3. ft Graphic Log Samples Sample No. % Recovery SPT, N value or RQD % Sheet 2 of 2 STANDARD PENETRATION TEST DATA N in blows/ft 1 2 3 4 REC% RQD % 2 4 6 8 STRENGTH, psf 77. 2. SAND (SP): fine grained; greenish gray; wet; loose to medium dense; lamination of sand at approximately 19.4 feet. (Continued) 6 6 1 6 C:\USERS\SLL\DESKTOP\PROJECTS\USS\USS SPIRIT LAKE GEOTECHNICAL.GPJ BARR ENGINEERING_LIB.GLB BOREHOLE LOG REPORT BARR ENGINEERING.GDT 7. 72. 7. 22. 2. 27. 3. 7.7 ft LEAN CLAY (CL): reddish brown; moist; laminations of sand. 69.9 ft SAND (SP): fine grained; greenish gray; wet. 69.1 ft LEAN CLAY (CL): reddish brown; moist. 67.7 ft SILTY CLAY (CL-ML): reddish brown; moist. 66.7 ft LEAN CLAY (CL): reddish brown; moist; soft. 34.-36.': Shelby tube, 18 inches recovery. 62.2 ft Date Boring Started: 11/9/11 Date Boring Completed: 11/9/11 Logged By: JD (EPC) Drilling Contractor: EPC Drill Rig: Bottom of Boring at 3. feet Water Levels (ft) 28.ft 28.8ft 29.6ft 31.ft 32.ft 36.ft 6 6 1 7 1 14 6 1 WH 1 92 Remarks: Vane shear testing performed and Shelby tubes (excluding 34-36.' Shelby tube) collected in an offset boring. Weather: 2 7 6 1 14

Project: Spirit Lake Sediment Site Job No.: 23/69-112.3-1-2 Location: Duluth, MN Coordinates: N 394,347.2 ft E 2,8,836.6 ft Datum: Elevation, feet Depth, feet Barr Engineering Company 332 W. Superior St. Suite 6 Duluth, MN 82 Telephone: 218-727-218 MATERIAL DESCRIPTION Surface Elevation: Drilling Method: Sampling Method: Completion Depth: LOG OF BORING WM-11 (314) 97.1 ft 3.2" HSA MC 3. ft Graphic Log Samples Sample No. % Recovery SPT, N value or RQD % Sheet 1 of 2 STANDARD PENETRATION TEST DATA N in blows/ft 1 2 3 4 REC% RQD % 2 4 6 8 STRENGTH, psf. 97.1 ft Surface Elev.: ORGANIC SILT (OL): black; wet. 1 C:\USERS\SLL\DESKTOP\PROJECTS\USS\USS SPIRIT LAKE GEOTECHNICAL.GPJ BARR ENGINEERING_LIB.GLB BOREHOLE LOG REPORT BARR ENGINEERING.GDT 9. 92. 9. 87. 8. 82. 8. 2.. 7. 1. 12. 1. 17. 9.6 ft PEAT (PT): very dark brown; wet; fibrous and silty. 9.1 ft SILT (ML): dark grayish brown; moist; trace to with sand..': Vane shear test. Lenses of sand at approximately 9 and 9.8 feet. Sandy at approximately 9. feet. 1.-12.': Shelby tube, no recovery. 1.': Vane shear test. 77. 2. Continued Next Page Date Boring Started: 11/1/11 Date Boring Completed: 11/1/11 Logged By: JD (EPC) Drilling Contractor: EPC Drill Rig: Water Levels (ft) 1.ft 2.ft 1 92 8 64 92 92 1 1 Remarks: Vane shear testing performed and Shelby tubes (excluding 27.-3.' shelby tube) were collected in an offset boring. Weather:

Project: Spirit Lake Sediment Site Job No.: 23/69-112.3-1-2 Location: Duluth, MN Coordinates: N 394,347.2 ft E 2,8,836.6 ft Datum: Elevation, feet Depth, feet Barr Engineering Company 332 W. Superior St. Suite 6 Duluth, MN 82 Telephone: 218-727-218 MATERIAL DESCRIPTION Surface Elevation: Drilling Method: Sampling Method: Completion Depth: LOG OF BORING WM-11 (314) 97.1 ft 3.2" HSA MC 3. ft Graphic Log Samples Sample No. % Recovery SPT, N value or RQD % Sheet 2 of 2 STANDARD PENETRATION TEST DATA N in blows/ft 1 2 3 4 REC% RQD % 2 4 6 8 STRENGTH, psf 2. SILT (ML): dark grayish brown; moist; trace to with sand. (Continued) 1 1 C:\USERS\SLL\DESKTOP\PROJECTS\USS\USS SPIRIT LAKE GEOTECHNICAL.GPJ BARR ENGINEERING_LIB.GLB BOREHOLE LOG REPORT BARR ENGINEERING.GDT 7. 72. 7. 67. 22. 2. 27. 3. Trace to with clay between approximately 22 and 2 feet. 27.-3.': Shelby tube, 18 inches recovery. 67.1 ft Date Boring Started: 11/1/11 Date Boring Completed: 11/1/11 Logged By: JD (EPC) Drilling Contractor: EPC Drill Rig: Bottom of Boring at 3. feet Water Levels (ft) 3.ft 1 1 Remarks: Vane shear testing performed and Shelby tubes (excluding 27.-3.' shelby tube) were collected in an offset boring. Weather:

Project: Spirit Lake Sediment Site Job No.: 23/69-112.3-1-2 Location: Duluth, MN Coordinates: N 394,638.3 ft E 2,81,61. ft Datum: Elevation, feet Depth, feet Barr Engineering Company 332 W. Superior St. Suite 6 Duluth, MN 82 Telephone: 218-727-218 MATERIAL DESCRIPTION Surface Elevation: Drilling Method: Sampling Method: Completion Depth: LOG OF BORING WM-12 (31) 97.8 ft 3.2" HSA MC 3. ft Graphic Log Samples Sample No. % Recovery SPT, N value or RQD % Sheet 1 of 2 STANDARD PENETRATION TEST DATA N in blows/ft 1 2 3 4 REC% RQD % 2 4 6 8 STRENGTH, psf 97.. 97.8 ft Surface Elev.: ORGANIC SILT (OL): very dark brown; wet; apparent black staining from contaminants. 1 2 C:\USERS\SLL\DESKTOP\PROJECTS\USS\USS SPIRIT LAKE GEOTECHNICAL.GPJ BARR ENGINEERING_LIB.GLB BOREHOLE LOG REPORT BARR ENGINEERING.GDT 9. 92. 9. 87. 8. 82. 8. 2.. 7. 1. 12. 1. 17. 9.3 ft LEAN CLAY (CL): very dark brown; wet. 93.3 ft SAND (SP): fine grained; very dark brown; wet. Fine to medium grained below approximately 6. feet. 89.8 ft SAND (SP): fine grained; very dark brown; wet; laminations of silt. 88.3 ft SANDY SILT (ML): fine grained; very dark brown; wet. 8.8 ft SAND (SP): fine to medium grained; very dark brown; wet; trace to with silt. 83.3 ft SILT (ML): very dark brown; wet; trace to with sand. 82.8 ft SAND (SP): fine to medium grained; very dark brown; wet; laminations of silt. 79.8 ft SILT (ML): very dark brown; wet; with sand to sandy, trace to with clay below approximately 19. feet. 2. 77.8 ft Continued Next Page Date Boring Started: 11/11/11 Date Boring Completed: 11/11/11 Logged By: JD (EPC) Drilling Contractor: EPC Drill Rig: Water Levels (ft) 2.ft 4.ft 8.ft 9.ft 12.ft 14.ft 1.ft 18.ft Remarks: Weather: 88 84 64 6 1 8 68

Project: Spirit Lake Sediment Site Job No.: 23/69-112.3-1-2 Location: Duluth, MN Coordinates: N 394,638.3 ft E 2,81,61. ft Datum: Elevation, feet Depth, feet Barr Engineering Company 332 W. Superior St. Suite 6 Duluth, MN 82 Telephone: 218-727-218 MATERIAL DESCRIPTION Surface Elevation: Drilling Method: Sampling Method: Completion Depth: LOG OF BORING WM-12 (31) 97.8 ft 3.2" HSA MC 3. ft Graphic Log Samples Sample No. % Recovery SPT, N value or RQD % Sheet 2 of 2 STANDARD PENETRATION TEST DATA N in blows/ft 1 2 3 4 REC% RQD % 2 4 6 8 STRENGTH, psf 77. 2. SILT (ML): very dark brown; wet; with sand to sandy. 2.ft 1 64 C:\USERS\SLL\DESKTOP\PROJECTS\USS\USS SPIRIT LAKE GEOTECHNICAL.GPJ BARR ENGINEERING_LIB.GLB BOREHOLE LOG REPORT BARR ENGINEERING.GDT 7. 72. 7. 22. 2. 27. 3. 73.3 ft SAND (SP): fine grained; very dark brown; wet. 72.3 ft SILTY SAND (SM): fine to medium grained; very dark brown; wet; lenses of wood chips. 7.3 ft SAND (SP): fine to medium grained; very dark brown; wet. 67.8 ft Date Boring Started: 11/11/11 Date Boring Completed: 11/11/11 Logged By: JD (EPC) Drilling Contractor: EPC Drill Rig: Bottom of Boring at 3. feet Water Levels (ft) 24.ft 2.ft 27.ft 3.ft Remarks: Weather: 6 1 1

Attachment F-2 Cone Penetration Test (CPT) Logs

EPC Engineering qt (tsf) 1 1 fs (tsf).. 1. 1. Job No: 11-411 Date: 1:2:11 11:48 Site: SPIRIT LAKE SEDIMENT STUDY u (ft) 1 2 3 Rf (%). 2.. 7. Sounding: CPT-33 Cone: 1:T1F1U SBT 6 12 Sensitive Fines 1 1 Ueq=13.8' y Clay Sensitive Fines Sandy Sandy y Sand/Sand Sandy Sandy Depth (feet) 2 2 3 3 Clayey Clayey Sandy Clayey Clayey Clayey Sensitive Fines Sensitive Fines Clayey 4 Clayey 4 Max Depth: 1.2 m /.3 ft Depth Inc:. m /.164 ft Avg Int:.1 m File: 11-411CP33.COR Unit Wt: SBT Chart Soil Zones Sensitive Fines Sensitive Fines Clayey Clayey SBT: Lunne, Robertson and Powell, 1997 Coords: Lat: 46.693 Long: -92.19621 Equilibrium Pore Pressure from Dissipation

EPC Engineering qt (tsf) 1 1 fs (tsf).. 1. 1. Job No: 11-411 Date: 1:2:11 14:1 Site: SPIRIT LAKE SEDIMENT STUDY u (ft) 1 2 3 Rf (%). 2.. 7. Sounding: CPT-34 Cone: 1:T1F1U SBT 6 12 Sensitive Fines Ueq=13.6' Sandy y Sand/Sand Sandy Sandy Depth (feet) 1 1 2 2 3 3 Sandy y Sand/Sand y Sand/Sand Sandy Sandy Sandy y Sand/Sand y Sand/Sand Sandy Clayey Sandy Sandy Clayey Clayey Sensitive Fines Clayey Sensitive Fines Clayey 4 Sensitive Fines 4 Sandy Max Depth: 1.2 m /.3 ft Depth Inc:. m /.164 ft Avg Int:.1 m File: 11-411CP34.COR Unit Wt: SBT Chart Soil Zones SBT: Lunne, Robertson and Powell, 1997 Coords: Lat: 46.69181 Long: -92.19818 Equilibrium Pore Pressure from Dissipation

EPC Engineering qt (tsf) 1 1 fs (tsf).. 1. 1. Job No: 11-411 Date: 1:26:11 13:27 Site: SPIRIT LAKE SEDIMENT STUDY u (ft) 1 2 3 Rf (%). 2.. 7. Sounding: CPT-3A Cone: :T1F1U SBT 6 12 Sensitive Fines 1 Ueq=14.8' Clay Sensitive Fines Sensitive Fines Sandy Clayey Clay 1 2 Depth (feet) 2 3 3 4 4 Max Depth: 3. m / 1.1 ft Depth Inc:. m /.164 ft Avg Int:.1 m File: 11-411CP3A.COR Unit Wt: SBT Chart Soil Zones SBT: Lunne, Robertson and Powell, 1997 Coords: Lat: 46.692 Long: -92.2243 Equilibrium Pore Pressure from Dissipation

EPC Engineering qt (tsf) 1 1 fs (tsf).. 1. 1. Job No: 11-411 Date: 1:26:11 11:11 Site: SPIRIT LAKE SEDIMENT STUDY u (ft) 1 2 3 Rf (%). 2.. 7. Sounding: CPT-3 Cone: :T1F1U SBT 6 12 Drilled Out Drilled Out Drilled Out Drilled Out Undefined 1 Sensitive Fines y Clay Sensitive Fines 1 Clay Depth (feet) 2 2 3 Clayey Clayey Clay y Clay Clay 3 Ueq=37.' 4 Clay 4 Refusal Refusal Refusal Refusal Max Depth: 14.9 m / 49. ft Depth Inc:. m /.164 ft Avg Int:.1 m File: 11-411CP3.COR Unit Wt: SBT Chart Soil Zones Ueq=49.7' y Clay Clay y Clay Clay y Clay Clay Sand SBT: Lunne, Robertson and Powell, 1997 Coords: Lat: 46.6927 Long: -92.2248 Equilibrium Pore Pressure from Dissipation

EPC Engineering qt (tsf) 1 1 fs (tsf).. 1. 1. Job No: 11-411 Date: 1:26:11 8:22 Site: SPIRIT LAKE SEDIMENT STUDY u (ft) 1 2 3 Rf (%). 2.. 7. Sounding: CPT-36 Cone: 1:T1F1U SBT 6 12 Sensitive Fines Clayey Clayey 1 Sensitive Fines y Clay Clay 1 y Clay Clay y Clay 2 Ueq=27.' Sensitive Fines y Sand/Sand Depth (feet) 2 Ueq=33.7' Sandy y Sand/Sand Clayey 3 Clayey Sensitive Fines 3 Clayey 4 4 Clayey Clayey Max Depth: 1.2 m /.3 ft Depth Inc:. m /.164 ft Avg Int:.1 m File: 11-411CP36.COR Unit Wt: SBT Chart Soil Zones SBT: Lunne, Robertson and Powell, 1997 Coords: Lat: 46.697 Long: -92.229 Equilibrium Pore Pressure from Dissipation

1 1 EPC Engineering qt (tsf) fs (tsf).. 1. 1. Job No: 11-411 Date: 1:27:11 8:3 Site: SPIRIT LAKE SEDIMENT STUDY u (ft) 1 2 3 Ueq=2.7' Rf (%). 2.. 7. Sounding: CPT-37 Cone: :T1F1U SBT 6 12 Clay Sensitive Fines Clay Clayey Clayey Sandy Clayey 1 1 Ueq=24.7' Sandy y Sand/Sand Sandy y Sand/Sand Sandy y Sand/Sand Depth (feet) 2 2 3 Sandy Sandy Clayey Clayey Clayey 3 Clayey 4 Sandy Clayey 4 Max Depth: 13. m / 44.4 ft Depth Inc:. m /.164 ft Avg Int:.1 m File: 11-411CP37.COR Unit Wt: SBT Chart Soil Zones SBT: Lunne, Robertson and Powell, 1997 Coords: Lat: 46.689 Long: -92.197 Equilibrium Pore Pressure from Dissipation

EPC Engineering qt (tsf) 1 1 fs (tsf).. 1. 1. Job No: 11-411 Date: 1:26:11 14:3 Site: SPIRIT LAKE SEDIMENT STUDY u (ft) 1 2 3 Rf (%). 2.. 7. Sounding: CPT-39 Cone: :T1F1U SBT 6 12 1 Drilled Out Drilled Out Drilled Out Drilled Out Undefined Sandy Sensitive Fines Clay Depth (feet) 1 2 2 3 3 4 Ueq=2.2' Ueq=3.' Clayey Sensitive Fines Sandy y Sand/Sand Sandy y Sand/Sand Sandy y Sand/Sand Clayey Clayey y Clay Clayey y Clay 4 Clayey Max Depth: 17. m /.94 ft Depth Inc:. m /.164 ft Avg Int:.1 m File: 11-411CP39.COR Unit Wt: SBT Chart Soil Zones Refusal Refusal Refusal Refusal SBT: Lunne, Robertson and Powell, 1997 Coords: Lat: 46.68864 Long: -92.233 Equilibrium Pore Pressure from Dissipation

EPC Engineering qt (tsf) 1 1 fs (tsf).. 1. 1. Job No: 11-411 Date: 1:26:11 14:3 Site: SPIRIT LAKE SEDIMENT STUDY u (ft) 1 2 3 Rf (%). 2.. 7. Sounding: CPT-39 Cone: :T1F1U SBT 6 12 Clayey Refusal Refusal Refusal Refusal 6 6 7 Depth (feet) 7 8 8 9 9 1 Max Depth: 17. m /.94 ft Depth Inc:. m /.164 ft Avg Int:.1 m File: 11-411CP39.COR Unit Wt: SBT Chart Soil Zones SBT: Lunne, Robertson and Powell, 1997 Coords: Lat: 46.68864 Long: -92.233 Equilibrium Pore Pressure from Dissipation

EPC Engineering qt (tsf) 1 1 fs (tsf).. 1. 1. Job No: 11-411 Date: 1:27:11 12:3 Site: SPIRIT LAKE SEDIMENT STUDY u (ft) 1 2 3 Rf (%). 2.. 7. Sounding: CPT-31 Cone: 1:T1F1U SBT 6 12 y Clay Sensitive Fines Sensitive Fines 1 Ueq=19.2' Sandy Sandy y Sand/Sand 1 Sandy y Sand/Sand 2 Sand Depth (feet) 2 Ueq=3.9' y Sand/Sand Sandy y Sand/Sand Sand 3 Clayey y Clay Sensitive Fines 3 Clayey Sensitive Fines 4 Clayey 4 Sensitive Fines Clayey Clayey Max Depth: 1.2 m /.3 ft Depth Inc:. m /.164 ft Avg Int:.1 m File: 11-411CP31.COR Unit Wt: SBT Chart Soil Zones SBT: Lunne, Robertson and Powell, 1997 Coords: Lat: 46.68398 Long: -92.22 Equilibrium Pore Pressure from Dissipation

1 1.. 1. 1. 1 2 3. 2.. 7. Drilled Out Drilled Out Drilled Out Drilled Out EPC Engineering qt (tsf) fs (tsf) Job No: 11-411 Date: 1:27:11 14:41 Site: SPIRIT LAKE SEDIMENT STUDY u (ft) Rf (%) Sounding: CPT-311 Cone: 1:T1F1U SBT 6 12 Undefined Clayey Sensitive Fines Sensitive Fines 1 1 2 Ueq=14.8' Ueq=23.4' Sandy y Sand/Sand y Clay y Sand/Sand Sandy Sand y Sand/Sand Sand Depth (feet) 2 3 3 y Sand/Sand Sand y Sand/Sand Sand Sandy y Sand/Sand Sandy y Sand/Sand Sandy Sandy 4 Clayey Sandy 4 Clayey Max Depth: 1.8 m / 2. ft Depth Inc:. m /.164 ft Avg Int:.1 m File: 11-411CP311.COR Unit Wt: SBT Chart Soil Zones Sandy Clayey Clayey SBT: Lunne, Robertson and Powell, 1997 Coords: Lat: 46.6823 Long: -92.2327 Equilibrium Pore Pressure from Dissipation

EPC Engineering qt (tsf) 1 1 fs (tsf).. 1. 1. Job No: 11-411 Date: 1:27:11 14:41 Site: SPIRIT LAKE SEDIMENT STUDY u (ft) 1 2 3 Rf (%). 2.. 7. Sounding: CPT-311 Cone: 1:T1F1U SBT 6 12 6 6 7 Depth (feet) 7 8 8 9 9 1 Max Depth: 1.8 m / 2. ft Depth Inc:. m /.164 ft Avg Int:.1 m File: 11-411CP311.COR Unit Wt: SBT Chart Soil Zones SBT: Lunne, Robertson and Powell, 1997 Coords: Lat: 46.6823 Long: -92.2327 Equilibrium Pore Pressure from Dissipation

1 1 1 EPC Engineering qt (tsf) fs (tsf).. 1. 1. Job No: 11-411 Date: 1:28:11 8:4 Site: SPIRIT LAKE SEDIMENT STUDY u (ft) 1 2 3 Rf (%). 2.. 7. Sounding: CPT-314 Cone: 1:T1F1U SBT 6 12 Sensitive Fines Clayey Clay Sandy Sensitive Fines y Clay y Clay Clayey Clayey Clayey 1 y Clay 2 Clayey Depth (feet) 2 Sensitive Fines Clayey Sensitive Fines 3 Ueq=4.2' Clayey 3 4 4 Ueq=44.8' Sandy Sandy Clayey Clayey Clayey Max Depth: 1.2 m /.3 ft Depth Inc:. m /.164 ft Avg Int:.1 m File: 11-411CP314.COR Unit Wt: SBT Chart Soil Zones SBT: Lunne, Robertson and Powell, 1997 Coords: Lat: 46.67788 Long: -92.19936 Equilibrium Pore Pressure from Dissipation

EPC Engineering qt (tsf) 1 1 fs (tsf).. 1. 1. Job No: 11-411 Date: 1:28:11 11:6 Site: SPIRIT LAKE SEDIMENT STUDY u (ft) 1 2 3 Rf (%). 2.. 7. Sounding: CPT-31 Cone: 1:T1F1U SBT 6 12 Sensitive Fines Sandy Ueq=12.4' y Sand/Sand Sandy y Sand/Sand 1 Sandy 1 Clayey Clayey Clayey Depth (feet) 2 2 Ueq=31.2' Clayey Clayey Sandy Clayey Clayey Sandy 3 Clayey Clayey 3 Ueq=43.1' Sandy y Sand/Sand Clayey 4 Clayey Clayey 4 Clayey Clayey Clayey Max Depth: 1.2 m /.3 ft Depth Inc:. m /.164 ft Avg Int:.1 m File: 11-411CP31.COR Unit Wt: SBT Chart Soil Zones SBT: Lunne, Robertson and Powell, 1997 Coords: Lat: 46.67883 Long: -92.19626 Equilibrium Pore Pressure from Dissipation

1 1 1 1 EPC Engineering qt (tsf) fs (tsf).. 1. 1. Job No: 11-411 Date: 1:28:11 13:3 Site: SPIRIT LAKE SEDIMENT STUDY u (ft) 1 2 3 Ueq=11.2' Ueq=16.' Rf (%). 2.. 7. Sounding: CPT-316 Cone: 1:T1F1U SBT 6 12 Sensitive Fines Clayey Sandy Sandy Sandy Clayey Sandy y Sand/Sand Sandy Sandy Clayey Clayey Sensitive Fines Depth (feet) 2 2 3 3 4 4 Ueq=26.6' Ueq=3.4' Sandy y Sand/Sand Sandy y Sand/Sand Sandy y Sand/Sand Sandy y Sand/Sand y Sand/Sand Sandy y Sand/Sand Sandy y Sand/Sand Sandy y Sand/Sand y Sand/Sand Sandy y Sand/Sand Sandy y Sand/Sand y Sand/Sand Sandy Max Depth: 1.2 m /.3 ft Depth Inc:. m /.164 ft Avg Int:.1 m File: 11-411CP316.COR Unit Wt: SBT Chart Soil Zones SBT: Lunne, Robertson and Powell, 1997 Coords: Lat: 46.67839 Long: -92.19219 Equilibrium Pore Pressure from Dissipation

Attachment F-3 Pore Pressure Dissipation (PPD) Plots

EPC Engineering Job No: 11-411 Date: 2-Oct-211 11:48:48 Site: SPIRIT LAKE SEDIMENT STUDY Sounding: CPT-33 Cone: 1 Cone Area: 1 sq cm 3. 2. 2. Pore Pressure (ft) 1. 1... 1 1 2 Time (s) Trace Summary: Filename: 11-411CP33.PPD Depth: 1.8 m /.9 ft Duration: 2. s U Min: 6.1 ft U Max: 28.3 ft 211 ConeTec Investigations Ltd. WT: -2.393 m / -7.81 ft Ueq: 13.8 ft

EPC Engineering Job No: 11-411 Date: 2-Oct-211 14:1:3 Site: SPIRIT LAKE SEDIMENT STUDY Sounding: CPT-34 Cone: 1 Cone Area: 1 sq cm 3. 2. 2. Pore Pressure (ft) 1. 1... -. 1 2 3 4 Time (s) Trace Summary: Filename: 11-411CP34.PPD Depth: 1.4 m / 4.93 ft Duration:. s U Min: -3.3 ft U Max: 2.2 ft 211 ConeTec Investigations Ltd. WT: -2.742 m / -8.996 ft Ueq: 13.6 ft

EPC Engineering Job No: 11-411 Date: 28-Oct-211 8:4:8 Site: SPIRIT LAKE SEDIMENT STUDY Sounding: CPT-314 Cone: 1 Cone Area: 1 sq cm 8. 6. Pore Pressure (ft) 4. 2.. 1 1 2 Time (s) Trace Summary: Filename: 11-411CP314.PPD Depth: 9.7 m / 31.824 ft Duration: 2. s U Min: 39.6 ft U Max: 6.3 ft 211 ConeTec Investigations Ltd. WT: -2. m / -8.382 ft Ueq: 4.2 ft

EPC Engineering Job No: 11-411 Date: 28-Oct-211 13:3:37 Site: SPIRIT LAKE SEDIMENT STUDY Sounding: CPT-316 Cone: 1 Cone Area: 1 sq cm 3. 2. 2. Pore Pressure (ft) 1. 1... 1 2 3 4 Time (s) Trace Summary: Filename: 11-411CP316.PPD Depth: 1.4 m / 4.77 ft Duration: 4. s U Min: 8. ft U Max: 19. ft 211 ConeTec Investigations Ltd. WT: -1.961 m / -6.434 ft Ueq: 11.2 ft

Attachment F-4 Flat Plate Dilatometer (DMT) Data

Barr Engineering Company DMT Spreadsheet- Data Summary Water Depth (ft): -4.66 St Louis River Duluth Works Sediment 23/69-112 UTM, Zone 16N - NAD 83 (m) Sounding No: UC-94 Northing:. October 29, 211 Easting:. 1 Depth Below Existing Ground Surface 2 Mayne, 199 3 Marchetti,198 4 Marchetti, 1997 Campanella and Robertson, 1991 6 Marchetti,198 7 Schmertman, 1981 Depth 1 A B po p1 u o s vo s vo ' E D ' 4 ' E D s u 6 (ft) (bar) (bar) (psf) (psf) (psf) I d K D (bar) K o OCR 2 OCR 3 (deg) (deg) R M (ksf) (psf) (psf) (ksf) 3.. 1.1.69.9 478 91 113.46 8. 7 1.7 4.3 9.6 2.3 1 12 96 36 4..8 1.3 1. 1.1 4 691 1.14 1.2 4 1.9.2 12.7 2. 8 24 14 19..8 1.7.93 1.4 63 791 188.82 7.1 18 1. 3.6 7.2 2.1 38 2 133 82 6..9 1.6 1.9 1.3 66 891 226.34 7.1 9 1. 3.6 7.2 2.2 19 243 161 41 7..9 1.7 1.8 1. 728 991 263.7.8 1 1.3 3..3 1.9 3 219 13 9 12. 1.2 3.3 1.32 3.1 14 1491 41 2.18 3.8 62.9 3.7 39. 1.6 129 27 17. 2. 8. 2.42 8.3 132 1991 639 3.32.8 24 1.3 37.9 4.1 2. 426 863 22. 2.1 4.3 2.16 4.1 1664 2491 827 1.43 3.4 67.9 3.2 38.7 1. 141 26 27. 2.1 3.7 2.19 3.4 1976 2991 11 1.1 2.6 44.7 1.3 1. 1.1 91 34 26 14 32. 2.9 4. 3.1 3.8 2288 3491 123.41 3.3 27.9 1.7 2.2 1.4 7 4 78 37. 3.2 3.6 26 3991 1391 1.7 2.7 67.7 1.4 1.6 1.2 141 4 379 17 s u 7 M P:\Duluth\23 MN\69\2369112 St Louis River Duluth Works Sediment\WorkFiles\N RI Report_212\Appendices\Appendix E Geotechnical Evaluation\Tables\Draft\DMT Barr Processed\DMT Spreadsheet.xlsx

Barr Engineering Company DMT Spreadsheet- Data Summary Water Depth (ft): -.8 St Louis River Duluth Works Sediment 23/69-112 UTM, Zone 16N - NAD 83 (m) Sounding No: UC-9 Northing:. October 29, 211 Easting:. 1 Depth Below Existing Ground Surface 2 Mayne, 199 3 Marchetti,198 4 Marchetti, 1997 Campanella and Robertson, 1991 6 Marchetti,198 7 Schmertman, 1981 Depth 1 A B po p1 u o s vo s vo ' E D ' 4 ' E D s u 6 (ft) (bar) (bar) (psf) (psf) (psf) I d K D (bar) K o OCR 2 OCR 3 (deg) (deg) R M (ksf) (psf) (psf) (ksf) 6.6.3 1.3.4 1. 762 111 249 7.42.7 21.1 2. #NUM!.9 44 37 7.8.3 1.3.44 1.1 834 1126 293 14.73.3 23.1 2.2 #NUM!.9 48 4 8.9.6 1.9.78 1.7 9 1241 336 2.64 2.2 32.6 32.7 37.2 1.1 67 76 9.9.8 3.1.93 2.9 967 134 373 4.2 2.6 68.7 33.7 37.9 1.3 143 191 14. 1.3 1.9 1.46 1.7 123 1799 4.27 3.3 8.8 1.7 2.2 1.4 17 22 18 23 19.6 1.6 2.2 1.82 2. 171 237 737.17 3. 6.8 1. 1.9 1.3 13 271 222 17 24. 2.2 6. 2.23 6.3 1878 28 922 3. 3. 141.8 34. 38.3 1. 29 43 29.6 1. 2 1.2 1.7 219 338 1113 3.73.3 19.1 19.2 #NUM!.9 4 34 34. 3.4 4.4 3.6 4.2 22 38 1298.2 3.9 21 1. 2. 2.8 1. 44 649 1 67 37.3 3.9 4.9 4.4 4.7 2676 479 143.24 4.1 23 1. 2.1 3.1 1.6 48 76 77 76 s u 7 M P:\Duluth\23 MN\69\2369112 St Louis River Duluth Works Sediment\WorkFiles\N RI Report_212\Appendices\Appendix E Geotechnical Evaluation\Tables\Draft\DMT Barr Processed\DMT Spreadsheet.xlsx

Barr Engineering Company DMT Spreadsheet- Data Summary Water Depth (ft): -1.7 St Louis River Duluth Works Sediment 23/69-112 UTM, Zone 16N - NAD 83 (m) Sounding No: UC-96 Northing:. October 29, 211 Easting:. 1 Depth Below Existing Ground Surface 2 Mayne, 199 3 Marchetti,198 4 Marchetti, 1997 Campanella and Robertson, 1991 6 Marchetti,198 7 Schmertman, 1981 Depth 1 A B po p1 u o s vo s vo ' E D ' 4 ' E D s u 6 (ft) (bar) (bar) (psf) (psf) (psf) I d K D (bar) K o OCR 2 OCR 3 (deg) (deg) R M (ksf) (psf) (psf) (ksf) 1.1.7 2..78 2.3 181 224 43 2.2 33.4 3 3.7 4.4 43.9 3.6 11 42 2.1.3.9.44.6 242 322 8.6 8.4 7 1.7 4.3 9.4 2.3 1 17 68 3 3.3.3.7.4. 314 437 123.18. 2 1.2 2.6 4.2 1.8 4 86 62 7 4.4.3.8.4. 386 2 167.4 3.3 4.8 1.7 2.1 1.4 8 68 4 1.4.3.8..6 447 61 24.37 2.9 4.8 1. 1.8 1.2 8 71 9 9 6.6.4.9.6.7 19 76 247.3 2.9 4.8 1. 1.8 1.2 8 88 72 9 7.7. 1.6.7 9 88 29.29 2.6 4.7 1.3 1. 1.1 8 89 76 9 8.7. 1.1.69.9 62 979 327.6 2.4 7.7 1.2 1.3 1. 1 91 79 16 9.8.6 1.2.79.9 723 194 37.3 2..7 1.3 1.4 1.1 11 19 93 12 11..7 2..86 1.8 79 128 413 1.99 2.4 33.6 33.2 37.6 1.2 68 8 12. 1.1 3.7 1.19 3. 86 137 4 2.96 3.6 8.9 3. 38.9 1.6 167 27 13.1 1.4 4.7 1.41 4.4 928 1422 493 3.17 4.1 16 1. 36.1 39.2 1.7 221 379 14.3 1.7.1 1.7 4.8 1 136 37 2.43. 17 1.2 37.1 39.7 1.9 224 419 1.3 1.9. 1.94.3 161 163 74 2.3.2 117 1.2 37.4 39.8 1.9 244 464 s u 7 M P:\Duluth\23 MN\69\2369112 St Louis River Duluth Works Sediment\WorkFiles\N RI Report_212\Appendices\Appendix E Geotechnical Evaluation\Tables\Draft\DMT Barr Processed\DMT Spreadsheet.xlsx

Barr Engineering Company DMT Spreadsheet- Data Summary Water Depth (ft): -4.7 St Louis River Duluth Works Sediment 23/69-112 UTM, Zone 16N - NAD 83 (m) Sounding No: WM-1 Northing:. October 29, 211 Easting:. 1 Depth Below Existing Ground Surface 2 Mayne, 199 3 Marchetti,198 4 Marchetti, 1997 Campanella and Robertson, 1991 6 Marchetti,198 7 Schmertman, 1981 Depth 1 A B po p1 u o s vo s vo ' E D ' 4 ' E D s u 6 (ft) (bar) (bar) (psf) (psf) (psf) I d K D (bar) K o OCR 2 OCR 3 (deg) (deg) R M (ksf) (psf) (psf) (ksf) 3..4 1.9.7 484 96 113.44 6.7 1.4 3.4 6.6 2.1 11 112 7 24 4..6 1.3.79 1. 46 696 1. 7.3 9 1. 3.7 7. 2.2 19 167 11 41..8 1.3.9 1. 68 796 188.16 7.3 4 1. 3.7 7. 2.2 8 27 137 17 1. 1 1. 1.1 1.2 92 1296 376.1 3.9 4 1. 2. 2.8 1. 8 191 147 12 1. 1.4 3.2 1.3 2.9 1232 1796 64 1. 3. 49.9 3.3 38.8 1. 13 12 2. 1.7 3. 1.78 3.3 144 2296 72 1.47 2.9 3.8 34.3 38.2 1.3 11 143 2. 3.1 6.6 3.9 6.4 186 2796 94 1. 4.9 11 1.1 37.1 39.7 1.8 24 434 3..7 7.8.82 7.6 2168 3296 1128.37 8.8 62 1.7 4. 1.2 2.4 129 191 998 37 3..6 7.8.71 7.6 248 3796 1316.42 7.2 66 1. 3.7 7.3 2.2 137 143 94 296 s u 7 M P:\Duluth\23 MN\69\2369112 St Louis River Duluth Works Sediment\WorkFiles\N RI Report_212\Appendices\Appendix E Geotechnical Evaluation\Tables\Draft\DMT Barr Processed\DMT Spreadsheet.xlsx